I was looking on stuff about Sarnia sirens and found this from October 2018 and I think those 3 sirens they are talking about in the article are the thunderbolts at the Suncor Refinery, now I can't confirm it yet but as of right now it seems like they might be replacing the Tbolts. Here is the article from Sarnia The Observer.
https://www.theobserver.ca/news/local-n ... r-upgrades
UPDATE: I am hearing from Model2 saying that sirens at the refinery are refinery owned so I think the Tbolts at Suncor Refinery are safe for now as this is only municipality owned sirens getting upgraded/replaced meaning the ATI's but I will be keeping an eye on the Tbolts and hope nothing happens to them.
- Sirens & Thunderbolts 1003